Jose Mourinho has made a veiled criticism of Roberto Martinez for the Everton manager's outspoken rebuke of Chelsea for their pursuit of John Stones.

Martinez was unhappy with John Terry's comments in praise of Toffees defender Stones, whom the Premier League champions have pursued this summer and had offers rebuffed.

"I'm not speaking about Everton or Stones. I'm just speaking in general," said Chelsea boss Mourinho who has agreed a new deal keeping him at Stamford Bridge until June, 2019.

"If I could, I would speak with you (the media) once in a month.

"And there are other people in football who, if they could, they would have a press conference every day. And I don't want to say anything else."

Chelsea, who begin their title defence at home to Swansea today at Stamford Bridge (5.30pm), have five first-team defenders and Mourinho is keen to recruit more, with a left-back high on the agenda, but he insists he is not preoccupied by the transfer window. Another concern is up front. Mourinho is uncertain whether Diego Costa will be fit to begin the Blues' title defence after his troublesome hamstring injury flared up once more, forcing the striker out of last Sunday's Community Shield loss to Arsenal.

"I don't know. I promise you, I don't know," Mourinho said.

"I think he's going to train with the team (on Friday evening).

"His reaction after that and his decision to be confident to play is another story."

Mourinho dismissed the suggestion Chelsea might need to buy another striker due to Costa being an ongoing fitness concern.

"Three is the perfect number and we have three," said Mourinho, who is prepared to field Loic Remy or Radamel Falcao against the Swans.

Manchester City manager Manuel Pellegrini admits he now has to deliver titles after signing a new-two year contract at the Etihad Stadium.

Pellegrini said: "It is very important for the club to trust in our work. I am very happy here at Manchester City so if both parties are happy we can continue. The support the club gives me is important.

"But you know in this profession you need results, so it is very important for me to have a good season and get good results.

"For me a good season with a big team is that you must win a title (trophy).